Vacuum cleaner and method for controlling the same

ABSTRACT

A vacuum cleaner according to an embodiment of the present invention includes a cleaner body having a moving unit; a suction unit configured to suction dust and air; a detecting unit configured to detect movement of the suction unit; and a control part configured to determine whether movement of the cleaner body is required, based on information detected by the suction unit, and to control the moving unit when the movement of the cleaner body is required, wherein the control part determines a target location to which the cleaner body will be moved, determines a moving route to the target location based on a detected obstacle, controls the moving unit so that the cleaner body is moved along the determined moving route, stops a motor when it is determined that the cleaner body is not in contact with a floor surface, and thus prevents a user&#39;s injury.

TECHNICAL FIELD

The present invention relates to a vacuum cleaner and a method forcontrolling the same.

BACKGROUND ART

Generally, a vacuum cleaner is an apparatus which suctions dust andforeign substances scattered on a surface to be cleaned using a suctionmotor installed inside a main body, and filters the dust and the foreignsubstances in the main body.

The vacuum cleaner having such a function may be classified into anup-right type in which a suction nozzle as a suction port is integrallyformed with the main body, and a canister type in which the suctionnozzle is in communication with the main body through a connection pipe.

Meanwhile, in Korean Patent Publication No. 2010-0053098 (published onMay 20, 2010), there is disclosed a vacuum cleaner.

The vacuum cleaner includes a wheel which enables a cleaner body to beeasily moved, and a driving part which drives the wheel. The vacuumcleaner detects a rotational and translational motion of a movingmember, and controls an operation of the driving part.

Since such a vacuum cleaner should have a structure which enables themoving member to be rotatable and also to simultaneously perform thetranslational motion, the vacuum cleaner has a complex structure. Also,since the vacuum cleaner may detect a mechanical motion and may move thedriving part, but may not exactly detect a user's actual movement, it isdifficult for the cleaner body to be exactly moved toward the user. Andsince the vacuum cleaner may not recognize an obstacle in advance, thereis a risk of colliding with the obstacle. When the user performs acleaning operation while holding the cleaner body to clean a space otherthan a floor, the moving member may perform the translational motion orthe rotational motion. In this case, since the wheel of the cleaner maybe rotated by the driving part, the user may be injured by the rotatingwheel, or the user's clothes may be caught in a gap between the wheeland the cleaner body.

DISCLOSURE OF INVENTION Technical Problem

The present invention is directed to providing a vacuum cleaner in whicha cleaner body is able to recognize an obstacle, and to move along auser's moving direction while avoiding the obstacle, and a method forcontrolling the same.

Solution to Problem

One aspect of the present invention provides a vacuum cleaner includinga cleaner body having a moving unit for movement; a suction unitconnected to the cleaner body, configured to suction dust and air and toguide the suctioned dust and air to the cleaner body, and having ahandle; a first detecting unit configured to detect movement of thesuction unit; a second detecting unit provided at the cleaner body todetect an obstacle; and a control part configured to determine a targetlocation to which the cleaner body will be moved, based on informationdetected by the first detecting unit, to determine a moving route to thetarget location based on the determined target location and the obstacledetected by the second detecting unit, and to control the moving unit sothat cleaner body is moved along the determined moving route.

The moving route may be an avoidance route along which the cleaner bodymoves while avoiding the obstacle.

Another aspect of the present invention provides a method forcontrolling a vacuum cleaner, including determining existence andabsence of an obstacle, and detecting movement of a suction unitconnected to a cleaner body, and setting a target location to which thecleaner body will be moved; determining a moving route of the cleanerbody based on the obstacle and the target location to which the cleanerbody will be moved; and controlling the cleaner body to be moved alongthe moving route.

Advantageous Effects of Invention

According to the proposed invention, when it is necessary to move thecleaner body in the direction in which a user moves, it is possible tobe moved while avoiding the obstacle on the route toward the destinationat which the user is located, and thus the cleaner body can be rapidlyand accurately moved in the direction which the user moves.

Also, since lifting-up of the cleaner body is detected, and the rotationof the wheels is controlled, the user can be prevented from beinginjured by the rotation of the wheels.

Also, since the rotation of the wheels is prevented when the lifting-upof the cleaner body is detected, the user's clothes can be preventedfrom being caught in a gap between the wheel and the cleaner body due tothe rotation of the wheels.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a vacuum cleaner according to oneembodiment of the present invention.

FIG. 2 is a block diagram of the vacuum cleaner according to oneembodiment of the present invention.

FIG. 3 is a flowchart illustrating a method for controlling the vacuumcleaner according to one embodiment of the present invention.

FIG. 4 is a view illustrating a plurality of departure routes of thecleaner body

FIG. 5 is a view illustrating a departure route of the cleaner body whenthe distance between the cleaner body and the obstacle is more than areference distance.

FIG. 6 is a view illustrating a departure route of the cleaner body whenthe distance between the cleaner body and the obstacle is the referencedistance or less.

FIG. 7 is a block diagram of a vacuum cleaner according to anotherembodiment of the present invention.

FIG. 8 is a flowchart illustrating a method for controlling the vacuumcleaner according to another embodiment of the present invention.

MODE FOR THE INVENTION

Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings.

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings that form a part hereof,and in which is shown by way of illustration specific preferredembodiments in which the invention may be practiced. These embodimentsare described in sufficient detail to enable those skilled in the art topractice the invention, and it is understood that other embodiments maybe utilized and that logical structural, mechanical, electrical, andchemical changes may be made without departing from the spirit or scopeof the invention. To avoid detail not necessary to enable those skilledin the art to practice the invention, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense.

Also, in the description of embodiments, terms such as first, second, A,B, (a), (b) or the like may be used herein when describing components ofthe present invention. Each of these terminologies is not used to definean essence, order or sequence of a corresponding component but usedmerely to distinguish the corresponding component from othercomponent(s). It should be noted that if it is described in thespecification that one component is “connected,” “coupled” or “joined”to another component, the former may be directly “connected,” “coupled,”and “joined” to the latter or “connected”, “coupled”, and “joined” tothe latter via another component.

FIG. 1 is a perspective view of a vacuum cleaner according to oneembodiment of the present invention, and FIG. 2 is a block diagram ofthe vacuum cleaner according to one embodiment of the present invention.

Referring to FIGS. 1 and 2, a vacuum cleaner 1 according to oneembodiment of the present invention may include a cleaner body 10 whichhas a suction motor 14 for generating a suction force, and a suctionunit 20 which is connected to the cleaner body 10 and suctions air andforeign substances on a floor surface.

The cleaner body 10 may include a moving unit for movement of thecleaner body 10. The moving unit may include a plurality of wheels 11and 12. The plurality of wheels 11 and 12 may be disposed at both sidesof the cleaner body 10. The plurality of wheels 11 and 12 may include afirst wheel 11 which is disposed at a right side of the cleaner body 10,and a second wheel 12 which is disposed at a left side thereof. Also,the moving unit may include one or more subsidiary wheels, but is notlimited thereto.

Therefore, the cleaner body 10 may be three-point (or more) supported onthe floor surface by the first and second wheels and one or moresubsidiary wheels, and may be two-point supported by the first andsecond wheels.

A dust container 40 in which dust separated from the air is stored maybe detachably connected to the cleaner body 10.

The suction unit 20 may include a suction nozzle 30 which is moved alongthe floor surface, and a connection unit which connects the suctionnozzle 30 to the cleaner body 10. The connection unit may include anextension pipe 24 which is connected to the suction nozzle 30, a handle22 which is connected to the extension pipe 24, and a connection hose 23which connects the handle 22 to the cleaner body 10.

The moving unit may further include a plurality of motors 15 and 16which rotate the plurality of wheels 11 and 12, respectively. Theplurality of motors 15 and 16 may include a first motor 15 and a secondmotor 16. The first motor 15 may rotate the first wheel 11, and thesecond motor 16 may rotate the second wheel 12. Each of the motors 15and 16 may be independently operated. By an independent operation ofeach of the motors 15 and 16, the cleaner body 10 may be automaticallymoved forward and backward, and may also turn left and right.

The vacuum cleaner 1 may further include a detecting part 50. Thedetecting part 50 may detect existence and absence of an obstacle. Forexample, the detecting part 50 may detect a distance from the obstacle.Also, the detecting part 50 may detect a distance from the floorsurface.

The detecting part 50 may include a light wave transmitting part and oneor more light wave receiving parts. The light wave transmitting parttransmits a light wave, and the one or more light wave receiving partsreceive the light wave which is transmitted from the light wavetransmitting part, and reflected by the obstacle or the floor surface.

The light wave transmitting part and the one or more light wavereceiving parts are provided at a lower side of the cleaner body 10, andmay be disposed toward an outside of the cleaner body 10.

For example, when a plurality of light wave receiving parts areprovided, one light wave receiving part may be disposed at a frontsurface of the cleaner body 10, and another light wave receiving partmay be disposed at a lower surface of the cleaner body 10. In this case,the light wave receiving parts may be disposed at a lower end of thefront surface of the cleaner body 10, a front end of the lower surfacethereof, or a corner thereof which is a connection portion between thefront surface and the lower surface of the cleaner body 10.Alternatively, the light wave receiving parts may be disposed at thefront surface of the cleaner body 10 to be spaced up and down, and eachof the plurality of detecting parts 50 may be configured tosimultaneously detect existence of the obstacle and the distance fromthe floor surface.

The light wave may be infrared light or an ultrasonic wave, and thedetecting part 50 is not limited to the embodiment, and any types ofsensors may be used as the detecting part 50.

The vacuum cleaner 1 may further include an ultrasonic wave transmittingpart 55 which transmits the ultrasonic wave, and an ultrasonic wavereceiving part 60 which receives the ultrasonic wave transmitted fromthe ultrasonic wave transmitting part 55. The ultrasonic wavetransmitting part 55 may be located at the suction unit 20. Theultrasonic wave transmitting part 55 may be located at the handle 22 orthe suction nozzle 30, but is not limited thereto.

A distance between the suction unit 20 and the cleaner body 10 may bemeasured using a distance between the ultrasonic wave transmitting part55 and the ultrasonic wave receiving part 60. That is, in thespecification, the distance between the ultrasonic wave transmittingpart 55 and the ultrasonic wave receiving part 60 is regarded as thedistance between the suction unit 20 and the cleaner body 10.

The ultrasonic wave receiving part 60 may be disposed at the cleanerbody 10. The ultrasonic wave receiving part 60 may include a pluralityof receiving parts 61, 62 and 63. Each of the plurality of receivingparts 61, 62 and 63 may receive the ultrasonic wave transmitted from theultrasonic wave transmitting part 55.

When the plurality of receiving parts 61, 62 and 63 are horizontally orvertically projected, lines which connect the plurality of receivingparts 61, 62 and 63 may form a polygon.

For example, the plurality of receiving parts 61, 62 and 63 may includea first receiving part 61, a second receiving part 62 and a thirdreceiving part 63. When the first to third receiving parts 61, 62 and 63are horizontally or vertically projected, lines which connect the firstto third receiving parts 61, 62 and 63 may form a triangle.

A part of the first to third receiving parts 61, 62 and 63 may bedisposed to have a different height from that of the other part thereof.Also, two of the first to third receiving parts 61, 62 and 63 may bedisposed to be horizontally spaced.

In the embodiment, the ultrasonic wave transmitting part 55 and theultrasonic wave receiving part 60 may be totally referred to as a firstdetecting unit, and the detecting part 50 may be referred to as a seconddetecting unit.

The vacuum cleaner 1 may further include a control part 70 whichcontrols the first motor 15 and the second motor 16. The control part 70determines a location of the ultrasonic wave transmitting part 55 basedon the ultrasonic wave received in the ultrasonic wave receiving part60, and may operate one or more of the first motor 15 and the secondmotor 16 when it is necessary to move the cleaner body 10 toward theultrasonic wave transmitting part 55 of which the location isdetermined.

In the case in which the ultrasonic wave transmitting part 55 isdisposed at the handle 22, when a cleaning operation is performed whilemoving the handle 22, the ultrasonic wave transmitting part 55 is movedalong with the handle 22. In this case, the distance between theultrasonic wave transmitting part 55 and the ultrasonic wave receivingpart 60 may be varied.

A movable distance of the handle 22 corresponds to a length of theconnection hose 23, and when the handle 22 is spaced apart from thecleaner body 10 in a predetermined distance, a force of moving thehandle 22 is applied to the cleaner body 10, and thus the cleaner body10 is moved forward.

At this point, when each of the motors 15 and 16 is not operated, aforce for moving the cleaner body 10 should be applied by a user. Inthis case, there is a problem that it is hard for the user. Therefore,in the embodiment, when a distance between the ultrasonic wavetransmitting part 55 and the cleaner body 10 is a predetermined distanceor more, the control part 70 may control the first motor 15 and thesecond motor 16 so that the cleaner body 10 is moved toward the handle22.

The control part 70 may determine a location of the obstacle based onthe light wave received in the detecting part 50, and may control thefirst motor 15 and the second motor 16 so that the cleaner body 10 ismoved while avoiding the obstacle.

More specifically, the control part 70 may produce a plurality ofdeparture routes based on the existence and absence of the obstacle andthe location thereof. And the control part 70 may select one of theplurality of departure routes as a route along which the cleaner body 10is actually moved. The selected departure route may be a part of amoving route from a current location of the cleaner body 10 to a targetlocation thereof.

A part or all of the plurality of departure routes may be avoidanceroutes for avoiding the obstacle. Alternatively, a part or all of theplurality of departure routes may be departure routes when the obstacledoes not exist.

The avoidance routes may include a route along which the cleaner body 10avoids the obstacle by moving forward and bypassing the obstacle orchanging a direction thereof, and a route along which the cleaner body10 moves backward and then moves forward to bypass the obstacle, orchanges a direction thereof to one side.

Hereinafter, a method for controlling the vacuum cleaner will bedescribed in detail. FIG. 3 is a flowchart illustrating a method forcontrolling the vacuum cleaner according to one embodiment of thepresent invention, FIG. 4 is a view illustrating a plurality ofdeparture routes according to one embodiment of the present invention,FIG. 5 is a view illustrating a departure route of the cleaner body whenthe distance between the cleaner body and the obstacle is more than areference distance, and FIG. 6 is a view illustrating a departure routeof the cleaner body when the distance between the cleaner body and theobstacle is the reference distance or less.

Referring to FIGS. 3 to 6, while a cleaning operation is performed usingthe vacuum cleaner 1, the detecting part 50 may detect the existence andabsence of an obstacle or the location of the obstacle when the obstacleexists (S1).

More specifically, a light wave is transmitted from the light wavetransmitting part, and the light wave receiving part receives the lightwave transmitted from the light wave transmitting part.

The control part 70 may determine a distance from the obstacle andrelative locations of the obstacle and the cleaner body 10 using thelight wave. For example, the control part 70 may determine the distancefrom the obstacle by calculating a time while the light wave transmittedfrom the light wave transmitting part is reflected by the obstacle andthen received by the light wave receiving part, and may also recognizean angle between the obstacle and the cleaner body 10 in considerationof a distance between each of the plurality of detecting parts 50 andthe obstacle. However, in the present invention, a method fordetermining the distance from the obstacle and the relative locations ofthe obstacle and the cleaner body 10 is not limited thereto.

The control part 70 may determine a movable area of the cleaner body 10based on the location of the obstacle, and may produce a plurality ofdeparture routes (S2).

As described above, a part or all of the plurality of departure routesmay be avoidance routes. Hereinafter, description will be provided onthe assumption that all of the plurality of departure routes are theavoidance routes. And the control part 70 produces the plurality ofdeparture routes along which the vacuum cleaner 1 can avoid theobstacle.

Referring to FIG. 4, the control part 70 may produce the departureroutes including, for example, a route A along which the vacuum cleaner1 moves forward and turns to one side (a left side or a right side), aroute B along which the vacuum cleaner 1 changes a direction to one side(the left side or the right side) and then moves forward, a route Calong which the vacuum cleaner 1 moves backward straightly, a route Dalong which the vacuum cleaner 1 moves backward and then turns to oneside (the left side or the right side) while moving forward, a route Ealong which the vacuum cleaner 1 moves backward, then changes thedirection to the left side or the right side and moves forward, and soon.

More specifically, referring to FIG. 5, when the distance between thecleaner body 10 and the obstacle O is more than a reference distance,the control part 70 may produce the route A along which the vacuumcleaner 1 moves forward and turns to one side, and the route B alongwhich the vacuum cleaner 1 changes the direction to one side and thenmoves forward.

Referring to FIG. 6, when the distance between the cleaner body 10 andthe obstacle O is the reference distance or less, the control part 70may produce the route C along which the vacuum cleaner 1 moves backwardstraightly, the route D along which the vacuum cleaner 1 moves backwardand then turns to one side while moving forward, and the route E alongwhich the vacuum cleaner 1 moves backward, then changes the directionand moves forward.

An ultrasonic wave may be transmitted from the ultrasonic wavetransmitting part 55. Then, the ultrasonic wave receiving part 60receives the ultrasonic wave transmitted from the ultrasonic wavetransmitting part 55 (S3).

The control part 70 determines a distance value between the ultrasonicwave transmitting part 55 and each of the receiving parts 61, 62 and 63based on the ultrasonic wave received by each of the receiving parts 61,62 and 63 (S4).

And the control part 70 determines a location of the ultrasonic wavetransmitting part 55 using a plurality of determined distance values(S5).

And the control part 70 determines whether it is necessary to move thecleaner body 10, based on the determined location of the ultrasonic wavetransmitting part 55 (S6).

In the embodiment, the case in which it is necessary to move the cleanerbody 10 may be a case in which the distance between the ultrasonic wavetransmitting part 55 and the cleaner body 10 is a first referencedistance or more. At this point, the control part 70 controls thecleaner body 10 to be moved in a direction which becomes closer to theultrasonic wave transmitting part 55. Accordingly, the cleaner body 10may move forward to the ultrasonic wave transmitting part 55. Here, thefirst reference distance may be varied according to the length of theconnection hose.

Also, even when the distance between the ultrasonic wave transmittingpart 55 and the cleaner body 10 is a second reference distance or less,it may be necessary to move the cleaner body 10. At this point, thecontrol part 70 controls the cleaner body 10 to be moved in a directionwhich becomes distant from the ultrasonic wave transmitting part 55.Accordingly, the cleaner body 10 may move backward in a directionopposite to the ultrasonic wave transmitting part 55. Here, the secondreference distance may be varied according to a user's stride, height orthe like. Here, the first reference distance may be defined greater thanthe second reference distance.

When the distance between the ultrasonic wave transmitting part 55 andthe cleaner body 10 is the first reference distance or more, the cleanerbody 10 is distant from the user, and thus for the user's convenience,forward movement of the cleaner body 10 is required. However, when thedistance between the ultrasonic wave transmitting part 55 and thecleaner body 10 is the second reference distance or less, backwardmovement of the cleaner body 10 is required to prevent collision withthe user.

Eventually, when the distance between the ultrasonic wave transmittingpart 55 and the cleaner body 10 is the first reference distance or moreor the second reference distance or less, the movement of the cleanerbody 10 is required.

As a result of determination in the operation S6, when the movement ofthe cleaner body 10 is required, the control part 70 produces aplurality of moving routes which are connected from the departure routeto a target location, and selects one of the plurality of moving routes(S7).

For example, the control part 70 produces the plurality of moving routeswhich extend from the departure route to the target location. Thecontrol part 70 may set the target location based on a distance betweenthe cleaner body 10 and the suction unit 20. Specifically, the targetlocation is determined based on the distance between the ultrasonic wavetransmitting part 55 and the ultrasonic wave receiving part 60, and maybe a plurality of points within an area in which a distance thereof isthe first reference distance or less and the second reference distanceor more. The control part 70 may set the target location by selectingone of the plurality of points.

Since the control part 70 may produce the plurality of moving routes byextending one departure route, the number of produced moving routes maybe the same as or greater than that of the departure routes.

And an optimal moving route of the plurality of produced moving routesmay be selected. For example, the optimal moving route may be a route ofthe plurality of produced moving routes which has the shortest distance.That is, a route of the plurality of produced moving routes in which amoving distance of the cleaner body 10 is the shortest may be selected.The shortest route may be realized with an algorithm, and may berealized with one of a Dijkstra algorithm, a Bellman-Ford algorithm, anA* algorithm and a Floyd-Warshall algorithm, but is not limited thereto.

The control part 70 operates one or more of the first motor 15 and thesecond motor 16 so that the vacuum cleaner 1 is moved along the selectedmoving route (S8).

For example, the cleaner body 10 may be moved forward or backward by apredetermined distance from a current position. That is, the controlpart 70 may control each of the motors 15 and 16 to be rotated. At thispoint, a moving distance of each of the wheels may be the same byharmonizing the number of revolutions, and the cleaner body 10 is movedforward or backward.

As another example, the cleaner body 10 may be controlled to be turnedto one side. To turn the cleaner body 10 to the left side, the controlpart 70 may control the first motor 15 and the second motor 16 so that aRPM of the second motor 16 is greater than that of the first motor 15.However, to turn the cleaner body 10 to the right side, the control part70 may control the first motor 15 and the second motor 16 so that theRPM of the first motor 15 is greater than that of the second motor 16.At this point, a turning radius may be controlled by changing adifferent between the RPM of the first motor 15 and the RPM of thesecond motor 16.

As still another example, the cleaner body 10 may be controlled so thatthe direction thereof is changed. To change the direction of the cleanerbody 10 to one side, the control part 70 may control the first motor 15and the second motor 16. At this point, an angle for a change ofdirection may be controlled according to the RPM of each of the motors15 and 16.

As the result of determination in the operation S6, when the movement ofthe cleaner body 10 is not required, that is, the distance between theultrasonic wave transmitting part 55 and the cleaner body 10 is thefirst reference distance or less and the second reference distance ormore, an ultrasonic wave signal is received again (S3), and a distancevalue to the ultrasonic wave transmitting part 55 is determined (S4),and the location of the ultrasonic wave transmitting part 55 isdetermined (S5), and then it is determined whether movement of thevacuum cleaner 1 is required (S6).

Meanwhile, the control part 70 may determine whether the wheels of thecleaner body 10 are not in contact with the floor surface, based on thedistance from the floor surface.

When it is determined that the wheels of the cleaner body 10 are not incontact with the floor surface, it may be determined that the movementof the cleaner body 10 is not required. That is, when the control part70 determines that the distance from the floor surface which is detectedby the detecting part 50 is a predetermined distance or more, it isrecognized as a case in which the movement of the cleaner body 10 is notrequired to prevent a user's injury, and thus the moving unit may becontrolled to be stopped.

Since the floor surface may serve as a reflecting surface of the lightwave, when the cleaner body 10 becomes distant from the floor surface(e.g., the cleaner body 10 is lifted up by the user), an amount of thelight wave received by the one or more light wave receiving parts isconsiderably reduced, and thus, the control part 70 may recognize thatthe wheels are not in contact with the floor surface.

According to the proposed embodiment, in the case in which the movementof the cleaner body 10 is required in a direction in which the usermoves, when an obstacle exists on a route along which the user moves toa destination, it is possible to avoid the obstacle, and the cleanerbody 10 may be rapidly and accurately moved in the direction in whichthe user moves.

Also, since lifting-up of the cleaner body 10 is detected, and rotationof the wheels is controlled, the user may be prevented from beinginjured by the rotation of the wheels.

Also, since the rotation of the wheels is prevented when the lifting-upof the cleaner body 10 is detected, the user's clothes may be preventedfrom being caught in a gap between the wheel and the cleaner body 10 dueto the rotation of the wheels.

FIG. 7 is a block diagram of a vacuum cleaner according to anotherembodiment of the present invention.

Referring to FIG. 7, a detecting part 50 according to another embodimentof the present invention may include a plurality of detecting parts 50.That is, the detecting part 50 may include a first detecting part 51 anda second detecting part 52.

For example, the first detecting part 51 may detect an obstacle, and thesecond detecting part 52 may detect a state of the cleaner body 10.

A detecting function of the first detecting part 51 which detects adistance from the obstacle and a location thereof is the same as that inthe previous embodiment. The second detecting part 52 may be used todetect whether the wheels of the cleaner body 10 is spaced apart fromthe floor surface.

When the cleaner body 10 is not in contact with the floor surface, theuser may be prevented from being injured by controlling the motor.

Like the first detecting part 51, the second detecting part 52 may be alight wave sensor which detects the distance from the floor surface.Therefore, when the cleaner body 10 is distant from the floor surface ina predetermined distance or more, it may be determined that the vacuumcleaner is not in contact with the floor surface, and thus the motor maybe stopped.

Alternatively, the second detecting part 52 may be an accelerationsensor or a gyro sensor. More specifically, when the cleaner body 10 islifted upward from the floor surface by the user, and an acceleration oran angular acceleration having a predetermined value or more isgenerated upward in a moment, the control part 70 may determine that thecleaner body 10 is not in contact with the floor surface, and may stopthe motor.

The embodiment may be applied to the cases in which the cleaner body 10is in three-point contact with the floor surface by the first and secondwheels and the subsidiary wheel and is in two-point contact with thefloor surface by only the first and second wheels without the subsidiarywheel.

FIG. 8 is a flowchart illustrating a method for controlling the vacuumcleaner according to another embodiment of the present invention.Referring to FIG. 8, while a cleaning operation is performed using thevacuum cleaner 1, a ultrasonic wave may be transmitted from theultrasonic wave transmitting part 55. Then, the ultrasonic wavereceiving part 60 receives the ultrasonic wave transmitted from theultrasonic wave transmitting part 55 (S10).

The control part 70 determines a distance value between the ultrasonicwave transmitting part 55 and each of the receiving parts 61, 62 and 63based on the ultrasonic wave received by each of the receiving parts 61,62 and 63 (S20).

And the control part 70 determines a location of the ultrasonic wavetransmitting part 55 using a plurality of determined distance values(S30).

And the control part 70 determines whether it is necessary to move thecleaner body 10, based on the determined location of the ultrasonic wavetransmitting part 55 (S40).

The control part 70 determines whether an obstacle is detected by thedetecting part 50 (S50).

In the operation S50, when the obstacle is detected, the control part 70determines an avoidance route which extends from the cleaner body 10 toa target location, based on the location of the obstacle, and thenoperates one or more of the first motor 15 and the second motor 16 sothat the vacuum cleaner is moved along the avoidance route to the targetlocation (S60).

In the operation S50, when the obstacle is not detected, the controlpart 70 produces a moving route which extends to the target location,and then operates the first and second motors (S70).

According to the proposed invention, since the cleaner body 10 may movealong a user's motion, the user does need to directly move the cleanerbody 10, and thus the user's convenience may be enhanced.

Also, since it is determined whether an obstacle exists on a route alongwhich the user moves to a destination, and it is possible to avoid theobstacle, the cleaner body 10 may be accurately moved in the directionin which the user moves.

In the specification, the ultrasonic wave transmitting part and theultrasonic wave receiving part are elements for detecting movement ofthe suction unit, and may be referred to as a detecting unit.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A vacuum cleaner comprising: a cleaner body having a moving unit formovement; a suction unit connected to the cleaner body, configured tosuction dust and air and to guide the suctioned dust and air to thecleaner body, and having a handle; a first detecting unit configured todetect a distance between the cleaner body and the suction unit; asecond detecting unit provided at the cleaner body to detect anobstacle; and a control part configured to control the moving unit,wherein the control part determines whether movement of the cleaner bodyis required based on a distance between the suction unit and the cleanerbody detected by the first detecting unit, and sets a target location towhich the cleaner body will be moved, and produces a plurality ofdeparture routes based on a location of the obstacle detected by thesecond detecting unit, and determines a moving route of the cleaner bodyfrom one of the plurality of departure routes to the target locationwhen the movement of the cleaner body is required.
 2. The vacuum cleaneraccording to claim 1, wherein the departure route is an avoidance routealong which the cleaner body avoids the obstacle.
 3. The vacuum cleaneraccording to claim 2, wherein the control part controls the cleaner bodyto be turned to a left or right side, and thus to avoid the obstacle. 4.The vacuum cleaner according to claim 2, wherein the control partcontrols the cleaner body to be moved backward in a predetermineddistance, then to be turned to a left or right side, and thus to avoidthe obstacle.
 5. The vacuum cleaner according to claim 1, wherein thefirst detecting unit comprises an ultrasonic wave transmitting partwhich is provided at the suction unit to transmit an ultrasonic wave,and an ultrasonic wave receiving part which is provided at the cleanerbody to receive the ultrasonic wave transmitted from the ultrasonic wavetransmitting part, and the control part controls the moving unit to movethe cleaner body based on a distance between the ultrasonic wavetransmitting part and the ultrasonic wave receiving part.
 6. The vacuumcleaner according to claim 5, wherein, when the distance between theultrasonic wave transmitting part and the ultrasonic wave receiving partis a first reference distance or more, the control part controls thecleaner body to be moved in a direction which becomes closer to theultrasonic wave transmitting part.
 7. The vacuum cleaner according toclaim 5, wherein, when the distance between the ultrasonic wavetransmitting part and the ultrasonic wave receiving part is a secondreference distance or less, the control part controls the cleaner bodyto be moved in a direction which becomes distant from the ultrasonicwave transmitting part.
 8. The vacuum cleaner according to claim 5,wherein, when the distance between the ultrasonic wave transmitting partand the ultrasonic wave receiving part is a first reference distance ormore or a second reference distance or less, the control part controlsthe cleaner body to be moved, and the first reference distance is longerthan the second reference distance.
 9. The vacuum cleaner according toclaim 1, wherein the control part determines a distance between a floorsurface and the cleaner body based on information detected by the seconddetecting unit, and controls the moving unit to be stopped when thedistance between the floor surface and the cleaner body is a referencedistance or more.
 10. The vacuum cleaner according to claim 9, whereinthe second detecting unit comprises a first detecting part which detectsthe obstacle, and a second detecting part which is used to determine thedistance between the floor surface and the cleaner body.
 11. A methodfor controlling a vacuum cleaner, comprising: determining existence andabsence of an obstacle, and producing a plurality of departure routesaccording to a distance between a cleaner body and the obstacle;detecting movement of a suction unit connected to the cleaner body, andsetting a target location to which the cleaner body will be moved;determining a moving route of the cleaner body from one of the pluralityof departure routes to the target location; and controlling a movingunit provided at the cleaner body so that the cleaner body is movedalong the moving route.
 12. The method according to claim 11, wherein,in the controlling of the cleaner body, the moving unit is controlled sothat the cleaner body is moved backward, turned to a left or right side,and then moved.
 13. The method according to claim 11, wherein, in thecontrolling of the cleaner body, the moving unit is controlled so thatthe cleaner body is turned to a left or right side, and then moved. 14.The method according to claim 11, wherein the cleaner body comprises adetecting part which detects a distance between a floor surface and thecleaner body, and the method further comprises controlling the movingunit so that the cleaner body is stopped when the distance between thefloor surface and the cleaner body is a reference distance or more. 15.The method according to claim 11, wherein, in the determining of thetarget location, whether movement of the cleaner body is required isdetermined based on a distance between the cleaner body and the suctionunit.